This research proposal is intended to identify and initially characterize events involved in the pathogenesis of lymphatic lesions produced by filarial nematodes. Brugia pahangi infections of mongolian jirds (Meriones unquiculatus) will be used as an animal model. The specific aims of the proposal will investigate the role of specific host immune effectors such as lymphocytes, and antibody and nonspecific effectors such as macrophages in the induction and/or modulation of these lesions. In addition, attempts will be made to further develop the in vivo model using the B. pahangi jird system to characterize in detail the events involved in development, maintenance and modulation of filarial induced granulomatous lesions. Obtaining the goals of this project would advance the understanding of the pathogenesis of lymphatic filariasis and thus, increase in the future, the feasibility of the control and amelioration of the tissue damaging lesions produced by these parasites.